Hey there, thanks for sharing!
Just wanted to throw out an idea - have you guys tried using an extension like this one?
It's super easy to set up and can download all of the content from fanbox in its original quality.
I got this link
from a friend.
It's already 196MB without the photos from her X, so I believe the photos in it are in their original quality too.
I'm not sure if I can get consistent updates from him though.
I'm not associated with the author of the chrome extension.
Thanks in advance!